Dropping constant factor does not seem that important to be honest. The important thing to be exposed to/take away was the logarithmic behaviour. I'm sure if you want to go be a seismologist you will quickly learn all the details. If people realise the magnitudes are exponentially more damaging , then isn't that sufficient for the general audience?
Sounds like what they teach casually is simplified well past the point of accuracy and possibly even particular usefulness.